make constant mock available for go1.20 and above

README.md

@@ -344,6 +344,8 @@ func TestPatchFunc(t *testing.T) {
 }
 ```
 
+NOTE: `Mock` and `Patch` supports top-level variables and consts, see [runtime/mock/MOCK_VAR_CONST.md](runtime/mock/MOCK_VAR_CONST.md).
+
 ## Trace
 It is painful when debugging with a deep call stack.
 
@@ -459,7 +461,9 @@ In conclusion, `xgo` and monkey are compared as the following:
 |Per-Instance Method Mock|Y|N|
 |Per-Goroutine Mock|Y|N|
 |Per-Generic Type Mock|Y|Y|
-|Closuer Mock|Y|Y|
+|Var Mock|Y|N|
+|Const Mock|Y|N|
+|Closure Mock|Y|Y|
 |Stack Trace|Y|N|
 |General Trap|Y|N|
 |Compatiblility|NO LIMIT|limited to amd64 and arm64|

README_zh_cn.md

@@ -339,6 +339,8 @@ func TestPatchFunc(t *testing.T) {
 }
 ```
 
+注意: `Mock`和`Patch`也支持对包级别的变量和常量进行mock, 见[runtime/mock/MOCK_VAR_CONST.md](runtime/mock/MOCK_VAR_CONST.md).
+
 ## Trace
 在调试一个非常深的调用栈时, 通常会感觉非常痛苦, 并且效率低下。
 
@@ -451,6 +453,8 @@ Xgo通过在IR(Intermediate Representation)重写来成功地避开了这些问
 |实例级别方法Mock|Y|N|
 |Goroutine级别Mock|Y|N|
 |范型特定实例Mock|Y|Y|
+|变量Mock|Y|N|
+|常量Mock|Y|N|
 |闭包/匿名函数Mock|Y|Y|
 |堆栈收集|Y|N|
 |通用拦截器|Y|N|

cmd/xgo/edit.go

@@ -49,11 +49,11 @@ func addContentAt(content string, beginMark string, endMark string, seq []string
 }
 
 func addContentAtIndex(content string, beginMark string, endMark string, seq []string, i int, before bool, addContent string) string {
-	offset, endOffset := strutil.SeqenceOffset(content, seq, i, before)
+	offset, endOffset := strutil.SequenceOffset(content, seq, i, before)
 	if offset < 0 {
 		panic(fmt.Errorf("sequence missing: %v", seq))
 	}
-	anotherOff, _ := strutil.SeqenceOffset(content[endOffset:], seq, i, false)
+	anotherOff, _ := strutil.SequenceOffset(content[endOffset:], seq, i, false)
 	if anotherOff >= 0 {
 		panic(fmt.Errorf("sequence duplicate: %v", seq))
 	}

cmd/xgo/patch_compiler.go

@@ -100,7 +100,7 @@ func patchCompilerInternal(goroot string, goVersion *goinfo.GoVersion) error {
 	if err != nil {
 		return fmt.Errorf("patching gc main:%w", err)
 	}
-	err = patchCompilerAstTypeCheck(goroot)
+	err = patchCompilerAstTypeCheck(goroot, goVersion)
 	if err != nil {
 		return fmt.Errorf("patch ast type check:%w", err)
 	}

cmd/xgo/patch_compiler_ast_type_check.go

@@ -1,6 +1,10 @@
 package main
 
-import "os"
+import (
+	"os"
+
+	"github.com/xhd2015/xgo/support/goinfo"
+)
 
 const convertXY = `
 if xgoConv, ok := x.expr.(*syntax.XgoSimpleConvert); ok {
@@ -57,37 +61,82 @@ if xgoConv, ok := x.expr.(*syntax.XgoSimpleConvert); ok {
 }
 `
 
+func getExprInternalPatch(mark string, rawCall string, checkGoVersion func(goVersion *goinfo.GoVersion) bool) *Patch {
+	return &Patch{
+		Mark:         mark,
+		InsertIndex:  5,
+		InsertBefore: true,
+		Anchors: []string{
+			`(check *Checker) exprInternal`,
+			"\n",
+			`default:`,
+			`case *syntax.Operation:`,
+			`case *syntax.KeyValueExpr:`,
+			`default:`,
+			"\n",
+		},
+		Content: `
+case *syntax.XgoSimpleConvert:
+kind := check.` + rawCall + `
+x.expr = e
+return kind
+`,
+		CheckGoVersion: checkGoVersion,
+	}
+}
+
 var type2ExprPatch = &FilePatch{
 	FilePath: _FilePath{"src", "cmd", "compile", "internal", "types2", "expr.go"},
 	Patches: []*Patch{
+		getExprInternalPatch("type2_check_xgo_simple_convert", `rawExpr(nil, x, e.X, nil, false)`, func(goVersion *goinfo.GoVersion) bool {
+			return goVersion.Major > 1 || goVersion.Minor >= 21
+		}),
+		getExprInternalPatch("type2_check_xgo_simple_convert_no_target", `rawExpr(x, e.X, nil, false)`, func(goVersion *goinfo.GoVersion) bool {
+			return goVersion.Major == 1 && goVersion.Minor < 21
+		}),
 		{
-			Mark:         "type2_check_xgo_simple_convert",
-			InsertIndex:  5,
-			InsertBefore: true,
+			Mark:        "type2_match_type_xgo_simple_convert",
+			InsertIndex: 1,
 			Anchors: []string{
-				`(check *Checker) exprInternal`,
+				`func (check *Checker) matchTypes(x, y *operand) {`,
 				"\n",
-				`default:`,
-				`case *syntax.Operation:`,
-				`case *syntax.KeyValueExpr:`,
-				`default:`,
+			},
+			Content: convertXY,
+			CheckGoVersion: func(goVersion *goinfo.GoVersion) bool {
+				return goVersion.Major > 1 || goVersion.Minor >= 21
+			},
+		},
+		{
+			Mark:         "type2_binary_convert_type_xgo_simple_convert",
+			InsertIndex:  2,
+			InsertBefore: true,
+			Anchors: []string{
+				`func (check *Checker) binary(x *operand`,
 				"\n",
+				`mayConvert := func(x, y *operand) bool {`,
 			},
 			Content: `
-case *syntax.XgoSimpleConvert:
-	kind := check.rawExpr(nil, x, e.X, nil, false)
-	x.expr = e
-	return kind
-`,
+			(func(x, y *operand){` + convertXY + `})(x,&y)
+			`,
+			CheckGoVersion: func(goVersion *goinfo.GoVersion) bool {
+				return goVersion.Major == 1 && goVersion.Minor >= 20 && goVersion.Minor < 21
+			},
 		},
 		{
-			Mark:        "type2_match_type_xgo_simple_convert",
-			InsertIndex: 1,
+			Mark:         "type2_binary_convert_type_xgo_simple_convert_can_mix",
+			InsertIndex:  2,
+			InsertBefore: true,
 			Anchors: []string{
-				`func (check *Checker) matchTypes(x, y *operand) {`,
+				`func (check *Checker) binary(x *operand`,
 				"\n",
+				`canMix := func(x, y *operand) bool {`,
+			},
+			Content: `
+			(func(x, y *operand){` + convertXY + `})(x,&y)
+			`,
+			CheckGoVersion: func(goVersion *goinfo.GoVersion) bool {
+				return goVersion.Major == 1 && goVersion.Minor < 20
 			},
-			Content: convertXY,
 		},
 		{
 			Mark:        "type2_comparison_xgo_simple_convert",
@@ -192,25 +241,30 @@ type XgoSimpleConvert struct {
 }
 `
 
-func patchCompilerAstTypeCheck(goroot string) error {
-	err := type2ExprPatch.Apply(goroot)
+func patchCompilerAstTypeCheck(goroot string, goVersion *goinfo.GoVersion) error {
+	// always generate xgo_extra file
+	syntaxExtraFile := syntaxExtra.Join(goroot)
+	err := os.WriteFile(syntaxExtraFile, []byte(syntaxExtraPatch), 0755)
 	if err != nil {
 		return err
 	}
-	err = type2AssignmentsPatch.Apply(goroot)
+	if goVersion.Major == 1 && goVersion.Minor < 20 {
+		// only go1.20 and above supports const mock
+		return nil
+	}
+	err = type2ExprPatch.Apply(goroot, goVersion)
 	if err != nil {
 		return err
 	}
-	err = syntaxWalkPatch.Apply(goroot)
+	err = type2AssignmentsPatch.Apply(goroot, goVersion)
 	if err != nil {
 		return err
 	}
-	err = noderWriterPatch.Apply(goroot)
+	err = syntaxWalkPatch.Apply(goroot, goVersion)
 	if err != nil {
 		return err
 	}
-	syntaxExtraFile := syntaxExtra.Join(goroot)
-	err = os.WriteFile(syntaxExtraFile, []byte(syntaxExtraPatch), 0755)
+	err = noderWriterPatch.Apply(goroot, goVersion)
 	if err != nil {
 		return err
 	}

cmd/xgo/patch_support.go

@@ -1,6 +1,10 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/xhd2015/xgo/support/goinfo"
+)
 
 type FilePatch struct {
 	FilePath _FilePath
@@ -17,9 +21,11 @@ type Patch struct {
 	Anchors []string
 
 	Content string
+
+	CheckGoVersion func(goVersion *goinfo.GoVersion) bool
 }
 
-func (c *FilePatch) Apply(goroot string) error {
+func (c *FilePatch) Apply(goroot string, goVersion *goinfo.GoVersion) error {
 	if goroot == "" {
 		return fmt.Errorf("requires goroot")
 	}
@@ -52,6 +58,9 @@ func (c *FilePatch) Apply(goroot string) error {
 
 	return editFile(file, func(content string) (string, error) {
 		for _, patch := range c.Patches {
+			if patch.CheckGoVersion != nil && !patch.CheckGoVersion(goVersion) {
+				continue
+			}
 			beginMark := fmt.Sprintf("/*<begin %s>*/", patch.Mark)
 			endMark := fmt.Sprintf("/*<end %s>*/", patch.Mark)
 			content = addContentAtIndex(content, beginMark, endMark, patch.Anchors, patch.InsertIndex, patch.InsertBefore, patch.Content)

cmd/xgo/version.go

@@ -3,8 +3,8 @@ package main
 import "fmt"
 
 const VERSION = "1.0.19"
-const REVISION = "7fd3f2b160c52c890d248efceb23a5e070156e0c+1"
-const NUMBER = 167
+const REVISION = "55018f6d640a578b197c4a03220e7a3122326f62+1"
+const NUMBER = 168
 
 func getRevision() string {
 	revSuffix := ""

patch/ctxt/ctxt_go1.20_and_above.go

@@ -0,0 +1,6 @@
+//go:build go1.20
+// +build go1.20
+
+package ctxt
+
+const EnableTrapUntypedConst = true

patch/ctxt/ctxt_non_go1.20.go

@@ -0,0 +1,6 @@
+//go:build !go1.20
+// +build !go1.20
+
+package ctxt
+
+const EnableTrapUntypedConst = false

patch/syntax/vars.go

@@ -595,8 +595,11 @@ func (c *BlockContext) trapValueNode(node *syntax.Name, globaleNames map[string]
 		// good to go
 	} else if decl.Kind == Kind_Const {
 		// untyped const(most cases) should only be used in
-		// serveral cases because runtime type is unknown
+		// several cases because runtime type is unknown
 		if decl.ConstDecl.Type == nil {
+			if !xgo_ctxt.EnableTrapUntypedConst {
+				return node
+			}
 			untypedConstType = getConstDeclValueType(decl.ConstDecl.Values)
 			var ok bool
 			explicitType, ok = c.isConstOKToTrap(node)
@@ -680,6 +683,9 @@ func (ctx *BlockContext) trapSelector(node syntax.Expr, sel *syntax.SelectorExpr
 	var untypedConstType string
 	if constInfo, ok := pkgData.Consts[sel.Sel.Value]; ok {
 		if constInfo.Untyped {
+			if !xgo_ctxt.EnableTrapUntypedConst {
+				return nil, true
+			}
 			untypedConstType = constInfo.Type
 			var ok bool
 			explicitType, ok = ctx.isConstOKToTrap(node)

runtime/core/version.go

@@ -7,8 +7,8 @@ import (
 )
 
 const VERSION = "1.0.19"
-const REVISION = "7fd3f2b160c52c890d248efceb23a5e070156e0c+1"
-const NUMBER = 167
+const REVISION = "55018f6d640a578b197c4a03220e7a3122326f62+1"
+const NUMBER = 168
 
 // these fields will be filled by compiler
 const XGO_VERSION = ""

runtime/mock/MOCK_VAR_CONST.md

@@ -0,0 +1,61 @@
+# API Summary
+When passing a variable pointer to `Patch` and `Mock`, xgo will lookup for package level variables and setup trap for accessing to these variables.
+
+Constant can only be patched via `PatchByName(pkg,name,replacer)`.
+
+# Limitation
+1. Only variables and consts of main module will be available for patching,
+2. Constant patching requires go>=1.20.
+
+# Examples
+## `Patch` on variable
+```go
+package patch
+
+import (
+    "testing"
+
+    "github.com/xhd2015/xgo/runtime/mock"
+)
+
+var a int = 123
+
+func TestPatchVarTest(t *testing.T) {
+	mock.Patch(&a, func() int {
+		return 456
+	})
+	b := a
+	if b != 456 {
+		t.Fatalf("expect patched variable a to be %d, actual: %d", 456, b)
+	}
+}
+
+```
+
+Check [../test/patch_const/patch_var_test.go](../test/patch_const/patch_var_test.go) for more cases.
+
+## `PatchByName` on constant
+```go
+package patch_const
+
+import (
+    "testing"
+
+    "github.com/xhd2015/xgo/runtime/mock"
+)
+
+const N = 50
+
+func TestPatchInElseShouldWork(t *testing.T) {
+    mock.PatchByName("github.com/xhd2015/xgo/runtime/test/patch_const", "N", func() int {
+        return 5
+    })
+    b := N*4
+
+    if b != 20 {
+        t.Fatalf("expect b to be %d,actual: %d", 20, b)
+    }
+}
+```
+
+Check [../test/patch_const/patch_const_test.go](../test/patch_const/patch_const_test.go) for more cases.

runtime/mock/README.md

@@ -1,4 +1,6 @@
 # API Summary
+> This document describes `Mock` and `Patch` for functions. For variables and consts, see [MOCK_VAR_CONST.md](./MOCK_VAR_CONST.md).
+
 Mock exposes 3 `Mock` APIs to users:
 - `Mock(fn, interceptor)` - for **99%** scenarios